The company provided TNW with a statement explaining that a security issue was brought to its attention on Tuesday, though it remains light on specifics:

Earlier today, Tumblr was notified of a security vulnerability introduced in our iOS app. We immediately released an update that repairs the issue and are notifying affected users. We obviously take these incidents very seriously and deeply regret this error.

No security alert has been made via the company’s Twitter account — which has close to 1 million followers — as yet, though the blog post does appear in the timeline of users that open the iOS app on their phone which will help spread word.

There is no update for the Android app, which appears to be unaffected by this issue.

Tumblr is one of the Web’s most popular blogging platforms. Bought by Yahoo for $1.1 billion in a deal that closed in June, its network of blogs see more than 300 million monthly unique visitors. Tumblr says there are 120,000 new signups every day with 900 posts published every second.

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